1. Field of the Invention
The present invention relates to a curvature sensor capable of sensing a shape of an endoscope and an endoscope apparatus including the curvature sensor.
2. Description of the Related Art
Conventionally, there has existed an endoscope including a shape detection probe. The shape detection probe can be bent integrally with a scope of the endoscope to sense a shape of the scope. The shape detection probe includes a curvature sensing fiber for transmitting detection light having different wavelength components and a light modulator provided at the curvature sensing fiber to modulate the intensity or wavelength of each of the different wavelength components of the detection light.
The shape detection probe senses a shape of the scope based on the intensity or wavelength of each of the wavelength components before and after the modulation of the light modulator and the distance between the light modulator and the exit end of the curvature sensing fiber. The number of light modulators is equal to that of wavelength components contained in the detection light, and the light modulators selectively absorb one of the different wavelength components (see Japanese Patent No. 4714570, for example).